KR101230979B1 - Highly elastomeric and paintable silicone compositions - Google Patents

Abstract

The present invention provides a highly elastic curable and paintable silicone composition. Paintable silicone compositions of the present invention include organopolysiloxanes, silicone functional crosslinkers, and organic polymers. Highly elastic curable and paintable silicone compositions have an elongation of at least 150% and are useful as paint sealants and caulks.

Description

HIGH ELASTIC AND PAINTABLE SILICONE COMPOSITION {HIGHLY ELASTOMERIC AND PAINTABLE SILICONE COMPOSITIONS}

This application is a continuation of US patent application Ser. No. 10 / 874,512, which is incorporated herein by reference and claims this as a priority.
The present invention relates to a highly elastic vulcanizable and paintable silicone sealant and extruder composed of one or two components exhibiting high elongation combined with good adhesion and weatherability. These are self-adhesive curable room temperature vulcanizable (RTV) silicone compositions with a wide range of properties ranging from low modules to high strength and can be designed to have compositions that exhibit excellent paintability and adhesion while maintaining the remarkable weatherability of silicone elastomers. have.

Silicone compositions are widely used in the construction industry as well as in other industries, such as the automotive, electronics, aerospace and consumer markets, because these materials can be used in various types of substrates such as glass, metals, ceramics and fibers. It has self-bonding adhesion to wood, leather, plastics and paper. In addition, low temperature flexibility, high temperature stability, good electrical insulation and chemical and UV resistance are inherent in silicone based products. Therefore, silicone extruders are widely used in various fields. However, a disadvantage of the cured silicone compositions is that they cannot be painted. The low surface energy of the silicone does not wet the surface of the cured silicone with latex or oil based paints. The paint shrinks on the silicon surface, creating a poor surface appearance, commonly referred to as "fish eyes" in the industry.

Research to improve the paintability of silicone compounds has been carried out by adding inorganic fillers to uncured silicone. For example, silicone sealants were formulated by adding needle-like, needle-like, calcium carbonate to the polyorganosiloxane. In such sealants, acicular particles are oriented on the surface of the sealant during curing. The surface of the cured sealant improves paintability, but the addition of acicular calcium carbonate causes other problems, such as low elasticity. The general high load of calcium carbonate required to achieve improved paintability adversely affects the elasticity of the silicone sealant, causing its tensile elongation to be lower than required.

Plasticizers can be added to counteract the negative effects of calcium carbonate on the elongation of silicon. However, the plasticizer degrades the paintability of the silicone sealant.

When cured, there is a need to provide a curable silicone composition that can be painted by various types of coatings. It is also desirable to provide silicone extruders, sealants, adhesives, and caulks that are paintable over long periods of time and maintain the inherent superior elasticity and other properties of silicone.

Summary of the Invention

The organopolysiloxane composition of the present invention is an organic polymer, an organic oligomer, or a combination of an organic polymer and an organic oligomer; Organopolysiloxane polymers; And crosslinkers. The composition may further include other additives to change the properties of the organopolysiloxane. The organic polymer can be homopolymers, copolymers having reactive or non-reactive end groups, and mixtures thereof. It has been found that such compositions, when cured, produce silicone sealants that exhibit good paintability and good weatherability.

The silicone composition of the present invention, when cured, can be painted without forming a "fish eye" on the painted surface and has an elongation of at least 150%. The elongation of the cured silicone composition may be at least 200%, at least 800%, or at least 1000%.

Curable silicone compositions of the present invention generally comprise from about 50% to about 95% (based on the weight of the total polymer) organopolysiloxane polymer; About 1% to about 10% (based on the weight of the organopolysiloxane) silicone functional crosslinker; And from about 5% to about 50% (based on the weight of the total polymer) of the dispersed organic polymer. Preferably the curable silicone composition comprises 55% to 93% by weight organopolysiloxane polymer. More preferably, the curable silicone composition comprises 57% to 91% by weight organopolysiloxane polymer.

Preferably, the curable silicone composition of the present invention comprises from 7% to 45% by weight of organic polymer. More preferably, the curable silicone composition comprises 9% to 43% by weight organic polymer.

Organopolysiloxane polymers preferably have two or more reactive functional groups on the polymer chain. Such reactive functional groups can be selected from hydroxyl, alkoxy, silicone alkoxy, acyloxy, methoxymo, amino, amido, aminooxy, alkenoxy, alkenyl, enoxy and mixtures thereof. Reactive functional groups are end groups, pendant groups, or combinations thereof.

Organic polymers used in the curable silicone compositions of the invention include silylated and unsilylated polyurethanes, silylated allyl terminated polyethers, polyethers containing one or more silicone functional groups, silylated and unsilylated Acrylic functional polymers, silylated and unsilylated butyl functional polymers, and copolymers and mixtures thereof.
The amount of organic polymer used to prepare the paintable and curable silicone compositions of the present invention depends on the organic polymer used. Organic polymers are based on the weight of the total polymer and include from about 15% to about 50% of silylated and unsilylated polyurethanes; About 15% to about 50% silylated allyl terminated polyether; About 15% to about 50% silylated allyl terminated acrylic polyether; About 15% to about 50% silicone functional group-containing polyether; About 10% to about 50% of silylated and unsilylated acrylic multipolymers; And from about 5% to about 50% of silylated and unsilylated butyl functional polymers.

The organopolysiloxanes used in the present invention preferably have a molecular weight of 20,000 to 100,000 g / mol. Organopolysiloxanes include two or more reactive groups, and silylated polyurethanes, unsilylated polyurethanes, silylated allyl terminated polyethers, polyethers containing silicone functional groups, silylated acrylic functional polymers, non Organic polymers selected from the group consisting of silylated acrylic functional polymers, silylated butyl functional polymers, unsilylated butyl functional polymers, and mixtures thereof. The reactive group can be selected from end groups, pendant groups, and combinations thereof.

Silicone crosslinking agents used in the paintable and curable silicone compositions of the present invention are oximes, alkoxysilanes, epoxyalkylalkoxysilanes, amido silanes, inosilanes, enoxysilanes, tetraethoxysilanes, methyltrimethoxysilanes, vinyls. Trimethoxysilane, glycidoxypropyltrimethoxysilane, vinyltris-isopropenoxysilane, methyltris-isopropenoxysilane, methyltris-cyclohexylaminosilane, methyltris-secondarybutylaminosilane, condensation curing Crosslinkers such as catalysts, and combinations thereof. Preferred oxime crosslinkers include vinyltrismethylethylmethoxymethoxysilane, methyltrismethylethylmethoxymethoxysilane, and combinations thereof.

According to the present invention, the paintable and curable silicone composition may be a one-part curable composition or a two-part curable composition. The paintable and curable silicone composition can be one of a thermoset system and a room temperature cure system. Paintable and curable silicones can be extrudants or in-situ cured systems.

Paintable and curable silicone compositions of the present invention may also further comprise from about 0.01% to about 2% (by total weight) of catalyst. Suitable catalysts include metal salts of carboxylic acids, organotitanates, platinum complexes, peroxides, and combinations thereof. Preferred catalysts comprising metal salts of carboxylic acids include dibutyltindilaurate, dibutyltindiacetate, dimethyltindi-2-ethylhexanoate, and combinations thereof. Preferred organo titanates include tetrabutyl titanate, tetra-n-propyl titanate, diisopropoxydi (ethoxyacetoacetyl) titanate, bis (acetylacetonyl) diisopropyl titanate and combinations thereof. Include.

Paintable and curable silicone compositions may further comprise from about 3% to about 60% (based on total weight) of reinforcing agents, semi-reinforcing agents, or combinations thereof. Some preferred reinforcing agents include hydrophobic treated fumed silica, untreated fumed silica, hydrophobic precipitated calcium carbonate, heavy calcium carbonate, talc, zinc oxide, polyvinyl chloride powder, soft acrylic polymers, and combinations thereof. Paintable and curable silicone compositions may further comprise from about 0.5% to about 2% (by total weight) of adhesion promoter.

및 이들의 조합을 포함한다.Preferred organic polymers used in paintable and curable silicone compositions are silylated polyurethane polymers. Such silylated polyurethane polymers may comprise a) reacting a diisocyanate compound with a polyol to form an intermediate selected from isocyanates or hydroxyl terminated polyurethane prepolymers; And b) silylating the intermediate. Preferably, the intermediate is silylated with an organic functional silane having one or more hydrolyzable groups. Some preferred hydrolyzable groups include (OCH ₃ ) ₃ , (OCH ₂ CH ₃ ) ₃ , oxymo, enoxy, isopropenoxy,

And combinations thereof.

Preferably, the organic functional silane has the formula:

R "-X-Si-R '

Wherein R 'is (OCH ₃ ) ₃ , (OCH ₂ CH ₃ ) ₃ , CH ₃ (OCH ₃ ) ₂ , or CH ₃ (OCH ₂ CH ₃ ) ₂ , other hydrolyzable groups such as oxymo Substituents, enoxy, and isopropenoxy; R ″ is selected from the group consisting of amino, ureido, mercapto, isocyanato, and epoxy; X is C ₁ to C _8. The molecular weight of the polyurethane prepolymer intermediate is in the range of 5,000 to 50,000 g / mol. Polyurethane prepolymer intermediates have an NCO: OH ratio in the range of 1.4: 1 to 3: 1 or an OH: NCO ratio in the range of 1.4: 1 to 3: 1.

The organic polymer may also be a silylated allyl terminated polyether, wherein the silylated allyl terminated polyether is derived by reacting a vinyl alkyl terminated polyol with a hydride functional silane. Preferably, the hydride functional silane is selected from the group consisting of triethoxysilane, trimethoxysilane, methyldiethoxysilane, methyldimethylsilane and combinations thereof.

The organic polymer may also be a polyether with silicone functional groups. Preferably, when the organic polymer is a polyether with silicone functional groups, the silicone functional groups are hydrolyzable silane groups. Preferred polyethers with silicone functional groups are polyethers having a molecular weight ranging from about 2,000 to about 50,000 g / mol.

The invention also relates to a method of making a curable silicone sealant composition.

DETAILED DESCRIPTION OF THE INVENTION

The organopolysiloxane composition of the present invention consists of a polymeric phase and silicone functional cross-linking system comprising a reactive organopolysiloxane polymer, an organic polymer / oligomer having limited compatibility with the reactive organopolysiloxane polymer. The organic polymer / oligomer phase may contain reactive organosylyl end groups, which may be subjected to vulcanization with a silicone functional crosslinking system bonded to the reactive organopolysiloxane polymer. In order to maintain the good weatherability of typical elastomeric silicones and good paintability other than standard silicone elastomers, the concentration of organic polymer / oligomer must be maintained in a precise range. Both elevated and reduced levels of organic polymer / oligomer phase will result in a loss of good paintability. Significant weather resistance of these compositions is evidenced by the absence of surface degradation after more than 20,000 hours of exposure in a Xenon Arc Weatherometer, as described below. The composition of the present invention can be coated with various paints even after curing for several weeks while maintaining the excellent elasticity inherent to the silicone.

As used herein, the term “semi-compatible organic polymer / oligomer” includes organic polymers and oligomers that are not completely compatible with the organopolysiloxanes used in the present invention. That is, the semi-compatible organic polymer / oligomer is not fully miscible with the organopolysiloxane of the present invention.

Paintable silicone compositions of the present invention are generally prepared by combining semi-compatible organic polymers / oligomers, crosslinkers, and other additives commonly used in silicone sealants and extrusion agents in the presence of reactive polysiloxane fluids.

Curable organopolysiloxane compositions of the present invention include reactive organopolysiloxane polymers, semi-compatible organic polymers / oligomers, crosslinkers, and optionally include adhesion promoters, reinforcing agents, rheology control agents, chain extenders, and the like. When the composition reacts, the resulting silicone sealant is paintable even after curing for a long time.

The curable organopolysiloxane composition comprises about 5% to about 50% by weight, preferably about 7% to about 45% by weight, more preferably about 9% to about 43% by weight of organic polymer / oligomer, about 50% And from about 55% to about 93% by weight, more preferably from about 57% to about 91% by weight of the organopolysiloxane polymer. When cured, the paintable silicone composition has an elongation of at least about 150%, or at least 200%, 400%, or 800%. Paintable silicone compositions described herein have been found to have an elongation of at least 1000%.

The polyorganosiloxane preferably contains at least two reactive functional groups on the polymer chain, preferably at its terminal portion. In other words, preferably the reactive functional group is a terminal group. Polyorganosiloxanes useful in the present invention are axes which may be hydroxyl groups or hydrolyzable groups such as silicon-bonded alkoxy groups, acyloxy groups, methoxymo groups, amino groups, amido groups, aminoxy groups, alkenoxy groups and the like. Polyorganosiloxanes containing synthetic functional groups.

Organopolysiloxane polymers have the following structural formula:

Wherein R ¹ and R ² are independently alkyl having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, preferably methyl, aromatic groups having 6 to 10 carbon atoms or substituted aromatic groups, preferably Is phenyl and n is a number such that the weight average molecular weight of the organopolysiloxane is from about 10,000 to about 200,000 g / mol, preferably from about 20,000 to about 100,000 g / mol. The polymer should also be understood to contain two or more reactive functional groups (X) therein, as noted above. The functional groups may be independently OH, or OR ³ , or N (R ⁴ ) ₂ , enoxy, acyloxy, oxymo, or aminooxy, and these functional groups may have a substituent at any suitable position. E.g,

Wherein R ³ to R ¹⁴ are independently alkyl or cycloalkyl having from about 1 to about 8 carbon atoms.

The organopolysiloxanes of the invention can be represented as follows:

One or more R groups are independently aromatic or alkyl-aromatics containing 1 to 8 carbon atoms or 6 to 20 carbon atoms and optionally containing one or more functional groups such as amines, hydroxyls, alkenes, alkoxy, and the like. The amount of functional group, ie m, is 1, 2 or 3.

The reactive functional group (X) can be OH, or OR ', or N (R'), or enoxy, or acyloxy, or oxymo, or aminooxy, or amido, wherein the reactive functional group is any suitable A substituent at C or N, R 'as having about 1 to about 8 alkyl atoms, and 6 to 20 carbon atoms as aromatic and alkyl-aromatic groups, wherein R' may optionally have one or more functional groups, such as Amine, hydroxyl, and the like. The organopolysiloxane fluid may further contain a combination of two or more different polysiloxanes and / or organopolysiloxanes having different molecular weights. Polysiloxanes are generally viscous liquids and can be purchased from several silicone manufacturers, such as Wacker Corporation, General Electric, Dow Corning and Rhone-Poulenc.

The paintable sealing compositions of the invention are generally cured by adding them to moisture or a hardener. Either conventional one-component or two-component curing systems can be used. In conventional one-component cure, organopolysiloxanes are converted to compounds having alkoxy, oxime, enoxy, amido, amino, or ethoxy blockers by methods known in the art and literature. Organic condensation catalysts such as dibutyl tin dilaurate, dibutyl tin diacetate, dimethyl tin di-2-ethylhexanoate, or dimethyl hydroxy tin oleate, or organotitane can be used. have.

The semi-compatible organic polymers / oligomers used in connection with the present invention can generally be mixed with each other with the general organic polymers, or functional free and reactive organopolysiloxane polymers, included in various known polymers having non-reactive or reactive functional groups. Is a polymer. The organic polymer may be a homopolymer, copolymer or mixture thereof, and the polymer may be a crosslinked or non-crosslinked polymer. Organic polymers include aromatic and aliphatic polyurethanes, polyurea, polyethers, polyesters, acrylics, polystyrenes, styrene butadiene, polybutadiene, butyl rubber, and mixtures thereof, with or without other organic functionalities bound. Aromatic and aliphatic polyurethanes can have different backbones such as polyesters, polyethers, polyacrylates, polybutadienes, polycarbonates, and the like and combinations thereof. In addition, they may have other functional groups such as acrylates, amides, maleic anhydride and the like.

Another suitable organic polymer is a reactive silylated aromatic or aliphatic polyurethane polymer from the above general polyurethane class. Polyurethane prepolymers have terminal capping groups whose ends are derived, in part or in whole, from silane groups or silane groups and one or more aromatic alcohols, or one or more aliphatic alcohols, or a combination of one or more aromatic alcohols and one or more aliphatic alcohols. end capped by one of the combination of groups).

Examples of suitable silanes corresponding to the above systems include N-phenylaminopropyltrimethoxysilane, N-ethylaminoisobutyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, And aminosilanes (eg γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane) and acrylic monomers (eg ethyl acrylate, 2-ethylhexyl acrylate, Reaction product of methyl acrylate, methyl methacrylate and glycidal acrylate), mercaptosilane, reaction product of metcaptosilane and monoepoxide, reaction product of epoxysilane and secondary amine, isocyanato propyl triethoxy Silanes, and ureido propyl trimethoxy silanes.

In another embodiment of the invention, the organic polymer is a silylated allyl terminated linear or branched polyether. The polyether backbone may have other functional groups such as acrylates, amides, maleic anhydride, and the like. The ends of the polymer may be end capped in part or in whole by either a silane group or a combination of silane groups and other end capping groups.

Another suitable class of organic polymers / oligomers are reactive silylated polyols, ie silylated reactive polyol polymers or oligomers. These polyols may be selected from polyesters, polyethers, polyacrylates, polybutadienes, polycarbonates, and the like. Silylation can be carried out as described above (see paragraph, in particular with discussion of silylation of hydroxyl terminated polyurethane prepolymers).

Optionally, the blocked one-component curing system may contain a crosslinker as described herein. In two-component curing systems, crosslinkers such as polyfunctional alkoxy silanes or oligomers and catalysts are kept separated from the organopolysiloxane until reaction. The amount of catalyst for a two-component system is generally higher than in a one-component system. Such curing systems are described in Maurice Morton, et al., Rubber Technology, 3rd Ed., Pp. 406-407, (1987). If two-component curing is used, the two-component curing may be a room temperature curable or thermoset material.

Various conventional crosslinkers may be suitable, but oxime and alkoxy crosslinkers such as vinyltris-methylethylketoxymosilane and methyltris-methylethylketoxymosilane, and alkoxysilanes such as methyltrimethoxysilane and vinyl Trimethoxysilane is preferred. Methyltrimethoxysilane is marketed, for example, under the trade name A-1630, and vinyltrimethoxysilane is, for example, from General Electric-OSI Specialties to trade name A-171. It is commercially available. Methyltris-methylethylketoxymosilane (MOS) is commercially available, for example under the trade name OS-1000, and vinyl tris-methylketoxymosilane is, for example, trade name OS-2000 by Honeywell Corporation. Is commercially available. Other crosslinking agents such as alkoxysilanes, epoxyalkylalkoxysilanes, amidosilanes, aminosilanes, enoxysilanes, etc., as well as tetraethoxysilanes, glycidoxypropyltrimethoxysilanes, vinyltris-isopropenoxy Silanes, methyltris-isopropenoxysilane, methyltris-cyclohexylaminosilane, and methyltris-secondarybutylaminosilane are suitable. Mixtures of crosslinkers may also be used. The amount of crosslinking agent is generally about 0.2 to about 20 parts by weight, preferably about 1 to about 10 parts by weight, more preferably about 1.5 to about 6.5 parts by weight, based on 100 parts by weight of the copolymer-organopolysiloxane. Additional curing crosslinkers may also be used with the alkenyl functional organopolysiloxane polymers. These crosslinkers can be pretreated with the polyorganosilane polymer.

Crosslinkers are used in amounts commonly used to prepare curable silicone elastic compositions. Those skilled in the art will be able to determine appropriate amounts for room temperature curable and thermally curable crosslinkers. The amount used will depend upon the particular crosslinker selected and the nature of the cured elastomer desired and can be readily determined by one skilled in the art.

Mixtures of polyorganosiloxanes and crosslinkers are generally cured at room temperature when exposed to moisture, but in some cases it is desirable to accelerate the rate of cure, ie shorten the time to cure the composition. In this situation, a catalyst can be used. Preferred catalysts include metal salts of carboxylic acids such as dibutyltindilaurate, dibutyltindiacetate, and dimethyltindi-2-ethylhexanoate; Organotitanates such as tetrabutyl titanate, tetra-n-propyl titanate, diisopropoxydi (ethoxyacetoacetyl) titanate, and bis (acetylacetonyl) diisopropyl titanate. Alternatively, heat curable materials may be used in addition to or in place of room temperature curable systems.

The paintable sealing composition described herein generally becomes tacky within about 0.05 to about 12 hours, preferably about 0.1 to about 2 hours, once curing is initiated. The seal is substantially cured, ie chemically crosslinked, within about 7 days, depending on the curing system, depth of cure, and especially the catalyst used. The seal typically cures completely at about 21 days at 25 ° C. and 50% humidity. However, in the case of extruded materials, they can be vulcanized while exiting the extruder.

Curable silicone compositions described herein can be prepared to pass a "paint adhesion tape test". According to this test specification, the "paint adhesion tape test" is described as ASTM test D3359 and is performed as described below. The sealing composition is attached to the surface and painted. A laser blade is used to form a cross cut, ie a grid cut, through the paint and sealant layers. A 0.5 inch wide and 4-inch long strip of transparent Scotch® brand attachment tape (3M Corporation) is securely attached to the precut cross-shaped area. Pull the tape strongly attached to the painted surface at 90 ° angle. If the paint remains intact on the surface of the sealant, it is treated as having passed the test.

Optionally, adhesion promoters may be added to the paint sealant. The amount of adhesion promoter can be readily determined by one skilled in the art. The amount of adhesion promoter in the paint sealant is generally 0 to about 10 parts by weight, preferably about 1 to about 8 parts by weight, more preferably about 2 to about 6 parts by weight, and even more per 100 parts by weight of the organosilicon polymer. Preferably from about 1.5 to about 3 parts by weight.

Although optional ingredients, adhesion promoters are very desirable; The amount of adhesion promoter allows the sealant to adhere to the substrate for a long time. Suitable classes of adhesion promoters are aminoalkyl, mercaptoalkyl, ureidoalkyl, carboxy, acrylate and isocyanurate functional silanes. Examples of suitable adhesion promoters include mercaptopropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, ureidopropyltrimethyl Oxysilane, bis-γtrimethoxysilylpropylurea, 1,3,5-tris-γ-trimethyloxysilylpropylisocyanurate, bis-γ-trimethoxysilylpropylmaleate and fumarate and γ-metha Krilloxypropyltrimethoxysilane.

Optionally, reinforcing agents may be added to the paintable sealing composition of the present invention. The amount of reinforcing agent is generally from 0 to about 250 parts by weight, preferably from about 30 to about 200 parts by weight, more preferably from about 20 parts by weight to about 150 parts by weight, even more preferably from about 10 parts by weight, based on the weight of the polymer. About 100 parts by weight.

The adjuvant, although optional, is very preferred, especially when the sealant is caulk. The reinforcement increases the tensile strength of the cured sealant and reduces the sagging of the uncured sealant. Adjuvants also act as thixotropic agents. Such reinforcing agents are finely ground particulates, and typically include both commonly known reinforcing and semi-reinforcing agents having a particle size of less than about 10 microns, preferably about 5 microns or less, more preferably about 0.1 microns or less. do. Suitable reinforcing agents include hydrophobic treated fumed silica, such as TS 720 from Cabot Corporation, or R-972 from Degussa Corporation, hydrophobic precipitated calcium carbonate, talc, zinc oxide, polyvinyl chloride powder And soft acrylates, such as the acrylates described in US Pat. No. 6,403,711B1, which is incorporated herein by reference. Other components may also be used in the sealing formulations in amounts of up to about 20 parts by weight, preferably about 0.01 to 15 parts by weight, per 100 parts by weight of copolymer and organopolysiloxane. In addition, extenders, fillers such as heavy calcium carbonate and diatomaceous earth are optionally used. Such extenders exhibit minimal or no reinforcing effect and / or exhibit minimal or thixotropic effect.

UV stabilizers may also optionally be added. Pigments or colorants, such as titanium dioxide, iron oxide, carbon black, are optionally used to affect the color of the sealant and / or act as an ultraviolet stabilizer. LTV inhibitors, anti-ozone agents are also optionally added.

The sealant may optionally contain a solvent such as an organic solvent in the uncured state to reduce viscosity.

Example

Example  One

In this example, about 43% by weight organic polymer (based on the total weight of organic and inorganic polymers) was used to prepare an intermediate module sealant having a shore-A of 15. The organic polymer consisted of silyl terminated polyurethane. The amounts are listed in Table 1 below.

Table 1

Composition Weight percentage 2400 cps. Silanol terminated dimethylpolysiloxanes  10.44 50,000 cps. Silanol terminated dimethylpolysiloxane polymer  23.43 Soft Acrylic Fillers (Thyxotropes)  19.38 Hydrophobic treated precipitated calcium carbonate   5.86 Hexamethyldisilazane   0.35 Hydrophobic Treated Heavy Calcium Carbonate   2.34 Acrylic functional plasticizer   7.14 Dimethylbis-secondary butylaminosilane   0.64 Methyltris-methylethylmethoxymethoxysilane   3.99 Trimethoxysilylalkyl terminated polyurethane  25.56 Aminoethylaminopropyltrimethoxysilane   0.86 Dibutyl tin dilaurate   0.01 Sum 100.00

The composition was cured and then painted to create a smooth painted surface free of "fish eyes." The composition was tested by paint adhesion test as described in the specification. The composition maintained excellent weather resistance as evidenced by no change in Shore-A and no surface cracks after exposure to UV over 20,000 hours in a Xenon weatherometer.

Example  2

In this example, an intermediate module sealant with Shore-A of 15 was prepared using about 29% by weight organic polymer (based on the total polymer). The organic polymers consisted of silyl terminated polyether polymers as shown in Table 2. The composition is designed to produce a paintable quick cure silicone sealant with intermediate modular properties while exhibiting good adhesion on plastic, glass and anodized aluminum.

Table 2

Composition Weight percentage 50,000 cps. Silanol terminated dimethylpolysiloxane polymer  25.46 20,000 cps. Silanol terminated dimethylpolysiloxane polymer  16.97 Hydrophobic treated precipitated calcium carbonate  33.94 Hexamethyldisilazane   0.85 Dimethylbis-secondary butylaminosilane   2.25 Vinyltris-methylethylketoxymosilane   1.70 Alkoxy silyl terminated polyether  16.97 Aminoethylaminopropyltrimethoxysilane   1.80 Dibutyl tin diacetate   0.06 Sum 100.00

The uncoated composition required a time of 15 minutes of no adhesion after 9 minutes of operation at the time of curing. The composition passed a weathering test of 20,000 hours (h) in a xenon arc weatherometer without exhibiting any observable surface change. The sealant had good paintability. The test maintained the paintability indefinitely as the sealant was demonstrated by a periodic paintability test conducted over 79 days. The painted composition was smooth and free of "fish eyes."

Example  3

In this example, about 24% by weight (based on the total polymer) of the organic polymer was used to prepare the intermediate module sealant. The organic polymers consisted of silyl terminated polyether polymers as described in Table 3 below.

TABLE 3

Composition Weight percentage 50,000 cps. Silanol terminated dimethylpolysiloxane polymer   3.83 20,000 cps. Silanol terminated dimethylpolysiloxane polymer  34.51 2400 cps. Silanol terminated dimethylpolysiloxane polymer   4.02 Vinyltris-methylethylketoxymosilane   1.53 Dimethylbis-secondary Butylaminosilane   2.037 Hexamethyldisilazane   0.84 Hydrophobic treated precipitated calcium carbonate  30.68 Soft acrylic filler   7.48 Alkoxy silyl terminated polyether polymer  13.42 Aminopropyltriethoxysilane   1.63 Dibutyl tin diacetate   0.023 Sum 100.00

The composition was cured after coating to create a smooth painted surface free of "fish eyes." The composition passed the paint adhesion test while maintaining excellent weather resistance as evidenced by no change in Shore-A and no surface cracking after exposure to UV over 20,000 hours (h) in a Xenon weatherometer. .

Example  4

In this example, an intermediate module sealant was prepared using about 26% by weight (based on total polymer) of organic polymer. The organic polymer consisted of an MDI terminated polyurethane polymer as described in Table 4 below.

Table 4

Composition Weight percentage 50,000 cps. Silanol terminated dimethylpolysiloxane polymer  26.12 20,000 cps. Silanol terminated dimethylpolysiloxane polymer  17.41 Vinyltris-methylethylketoxymosilane   2.394 Dimethylbis-secondary Butylaminosilane   1.22 Hexamethyldisilazane   0.871 Hydrophobic treated precipitated calcium carbonate  34.83 MDI Terminated Polyurethane Prepolymer  15.24 Aminopropyltriethoxysilane   1.85 Dibutyl tin diacetate   0.065 Sum 100.00

The composition was cured and then painted to create a smooth painted surface free of "fish eyes." The composition passed the paint adhesion test while maintaining good weather resistance as evidenced by no surface cracks after exposure to UV over 20,000 hours (h) in a Xenon weatherometer.

Example  5

In this example, a silicone sealant was prepared using about 31% by weight organic polymer (based on the total polymer). The organic oligomers consisted of oxymo silane terminated polyether polyols as described in Table 5 below. Oxymo silane terminated polyether polyols were prepared by prereacting it with vinyl-methylethylketoxymosilane.

Table 5

Composition Weight percentage 50,000 cps. Silanol terminated dimethylpolysiloxane polymer  24.90 20,000 cps. Silanol terminated dimethylpolysiloxane polymer  16.60 Vinyltris-methylethylketoxymosilane   2.90 Oxymo Silane Terminated Polyether Polyols  17.43 Dimethylbis-secondary Butylaminosilane   2.20 Hexamethyldisilazane   0.95 Hydrophobic treated precipitated calcium carbonate  33.20 Aminopropyltriethoxysilane   1.76 Dibutyl tin diacetate   0.06 Sum 100.00

The composition was cured after coating to create a smooth painted surface free of "fish eyes." The composition passed the paint adhesion test while maintaining excellent weather resistance as evidenced by no change in Shore-A and no surface cracking after exposure to UV over 20,000 hours (h) in a Xenon weatherometer. .

Example  6

In this example, a paint sealant was prepared using about 15% by weight of organic polymer (based on the total polymer). The sealant had a Shore-A hardness of 40, an elongation of 760% and a tensile strength of 220 psi. The organic polymers consisted of acrylic terpolymers and polyether polyols as described in Table 6 below.

Table 6

Composition Weight percent 50,000 cps. Silanol terminated polydimethylsiloxane polymer  24.42 20,000 cps. Silanol terminated polydimethylsiloxane polymer  16.28 Hydrophobic precipitated calcium carbonate  32.56 Heavy calcium carbonate   7.79 Talc   0.90 Titanium dioxide   0.26 Hexamethyldisilazane   0.81 Dimethylbis-secondary Butylaminosilane   2.16 Vinyltris-methylethylketoxymosilane   1.63 Ethyl Acrylate Acrylonitrile Acrylic Acid Terpolymer   6.81 Polyether polyols   0.20 Butyl benzyl phthalate   0.77 menstruum   2.77 Ceramic fiber   0.85 Aminoethylaminopropyltrimethoxysilane   1.73 Dibutyl tin diacetate   0.06 Sum 100.00

The sealant was cured and then coated with acrylic latex paint. The painted surface was smooth and there was no “fish eye”. After 3 days of painting, the surface was tested by a paint adhesion test and no dropout of paint was observed.

Example  7

In this example, a paint sealant was prepared using about 9% by weight of organic polymer (based on the total polymer). The sealant had a Shore-A hardness of 43 and had an elongation of 355% and a tensile strength of 300 psi. The organic polymer was composed of isobutylene-isoprene copolymer and polybutene and hydrocarbon resin pressure sensitive adhesive as described in Table 7 below.

Table 7

Composition Weight percent 50,000 cps. Silanol terminated dimethylpolysiloxane polymer  24.42 20,000 cps. Silanol terminated dimethylpolysiloxane polymer  16.28 Hydrophobic precipitated calcium carbonate  32.56 Heavy calcium carbonate  11.14 Titanium dioxide   0.27 Magnesium carbonate   0.22 Crystalline silica   0.09 Hexamethyldisilazane   0.81 Dimethylbis-secondary Butylaminosilane   2.16 Vinyltris-methylethylketoxymosilane   1.63 Polybutene   2.81 Isobutylene Isoprene Copolymer   1.14 Hydrocarbon resin   0.24 Castor oil   0.24 menstruum   2.89 Aminoethylaminopropyltrimethoxysilane   1.73 Dibutyl tin diacetate   0.06 Sum 100.00

The resulting sealant was painted and tested in the same manner as described above. The painted surface was smooth and there was no “fish eye”. The composition passed the paint adhesion test while maintaining good weather resistance as evidenced by no change in Shore-A and no surface cracks.

The examples included herein are merely illustrative and are not intended to limit the scope of the invention.

Claims (95)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A curable silicone composition which exhibits an elongation of at least 150% upon curing and can be painted without the formation of a fish eye, a) one or more reactive organopolysiloxane polymers having a weight average molecular weight of 10,000 to 200,000, based on the total polymer; b) 1 to 10% by weight of one or more silane functional crosslinkers based on the weight of the organopolysiloxane; And c) a curable silicone composition comprising a semi-compatible polymer component comprising at least 5-50% by weight of the following polymers and oligomers, based on the total polymer: silylated polyurethane, From MDI-terminated polyurethanes, reactive silylated polyols, wherein the polyols are at least one of polyesters, polybutadienes and polycarbonates, non-silylated acrylic polymers, and styrene butadiene, polybutadiene and butyl rubbers Silyzed or non-silylated butyl functional polymer of choice. 71. The two or more organopolysiloxane polymers of claim 70, wherein the organopolysiloxane polymer is selected from the group consisting of hydroxyl, alkoxy, acyloxy, oxymo, amino, amido, aminoxy, alkenoxy, enoxy and mixtures thereof. Curable silicone composition containing the above reactive functional groups. 72. The curable silicone composition of claim 71 wherein the weight average molecular weight of the organopolysiloxane polymer is from 20,000 to 100,000. The curable silicone composition of claim 70 wherein the semi-compatible polymer is a silylated polyurethane polymer. 74. The curable silicone composition of claim 73 wherein said silylated polyurethane polymer is silylated with an organic functional silane having at least one hydrolyzable group. 75. The method according to claim 74, wherein the hydrolyzable groups are (OCH ₃ ) ₃ , (OCH ₂ CH ₃ ) ₃ , oxymo, enoxy, isopropenoxy,

And a combination thereof. 75. The curable composition of claim 74, wherein the organic functional silane is of the formula: R "-X-Si-R ' Where R ′ is from the group consisting of (OCH ₃ ) ₃ , (OCH ₂ CH ₃ ) ₃ , CH ₃ (OCH ₃ ) ₂ , CH ₃ (OCH ₂ CH ₃ ) ₂ , oxymo, enoxy, and isopropenoxy Selected; R ″ is selected from the group consisting of amino, ureido, mercapto, isocyanato, and epoxy; X is C ₁ to C ₈ . 75. The curable silicone composition of claim 74 wherein the weight average molecular weight of the silylated polyurethane is in the range of 5,000 to 50,000 g / mol. 78. The curable silicone composition of claim 77 wherein the silylated polyurethane has an NCO / OH ratio in the range of 1.4: 1 to 3: 1. The curable silicone composition of claim 70 wherein the semi-compatible polymer is an MDI-terminated polyurethane. The composition of claim 70, wherein the semi-compatible organic polymer or oligomer comprises from 15 to 50% by weight reactive silylated polyol based on the total polymer, wherein the polyol is selected from polyesters, polyacrylates, polybutadienes and Curable silicone composition of at least one of polycarbonates. The curable silicone composition of claim 70, wherein the semi-compatible organic polymer or oligomer comprises 10 to 50 weight percent non-silylated acrylic polymer based on the total polymer. The curable of claim 70, wherein the semi-compatible organic polymer or oligomer comprises 5 to 50 weight percent silylated or non-silylated butyl functional polymer based on the weight of components a) and c). Silicone composition. 70. The curable silicone composition of claim 70, wherein the curable silicone composition exhibits at least 400% elongation upon curing. 84. The curable silicone composition of claim 83 having an elongation of at least 800% upon curing. delete delete delete delete delete delete delete delete delete delete delete